1. Field of the Invention
The present invention relates to a linear motion mechanism which uses the elasticity of springs.
2. Description of the Related Art
With the increasing market demand for precision technology, a linear motion actuator providing high precision has become important for machinery requiring precise displacement such as multiple-degree-of-freedom displacement mechanism, micro-manipulator or the like. In most cases, such a fine linear motion actuator employs reduction gearing mechanism, which requires not only a plurality of parts such as different gears but also backlash adjustment of gears and other alignments during its assembly.
In order to eliminate the need of backlash adjustment and other alignments, there has been proposed a simplified linear motion mechanism using a combination of elastic plates to allow fine linear displacement (see Japanese Patent Unexamined Publication No. JP2003-075572). More specifically, two elastic plates are fixed to a fixed block at one ends and to a movable block at the other ends. The two elastic plates placed in parallel are connected by a curve elastic plate in the approximate shape of a letter H. The movable block is supported by an elastic plate orthogonal to a plane formed by the H-shaped elastic plates. The curve elastic plate is connected to the slider of a micrometer at the center thereof. Accordingly, extension or contraction of the slider causes the curve elastic plate to push or pull the parallel elastic plates in widening or narrowing directions, which linearly moves the movable block in the retracting or extending direction.